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Hi Jan - by 3-4K do you mean Rupia or USD? Peter

Hi Thomas - I think wacking the beam is the issue. Why not just bend it by hand a bit and let it go? Peter

Hi PIO - A moonshot thought for you. But I think the reinforcement cage is an error... Peter

https://www.mmsonline.com/articles/inside-oak-ridges-3d-printed-machine-tool-moonshot(2)

Evening all - Some more stuff on HP concrete. I am contemplating 3D printing a part "skin" in plastic then inserting the inserts then filling with grout as a test part. Hmmm. Peter

Fiber...

Hi Pio - For steel I'd call thin 3mm. I use a lot of 3mm laser cut steel. This is because its the thickest steel that is zinc plated. So I don't have to paint it. But then I also laminate it so I can...

Hi Thomas - Now I know what you mean by high/low Ta. I like pictures... Yes your maths checks out... :) So your bar has a zeta (loss factor or damping factor ) of around 0.01 a bit to go to get to...

Hi Thomas - The decrement should be the same, what is the voltage peaks in this image from your test? The decrement calc can be across two peaks as per decrement 1 image. Or it can be across several...

Hi BH - If the part has lots of short moves and corners then the max speed setting does not matter as the machine never reaches the higher speed. To move faster in this case you need to up the...

Hi Thomas - Is this the correct interpretation of your data? Could you draw the rough values and graph please? Ta Peter

Hi Thomas - My research into material damping has been similiar. It seems to be more of a comparative effort more than a defined science. Although the maths are clear the results are always variable....

Hi Jubee - double strength vinegar works a treat (normal vinegar to just takes longer) and is friendly on the skin... If you can put it in something and soak it the rust will be gone overnight. A...

Hi Sus - On the point of chips - any flat surface will accumulate chips and muck. So even the flat at the bottom of the column (ballscrew channel) will fill up so open that to the bottom as well....

Hi Thomas - To calculate the logarithmic decrement you only need two peaks. See wiki - Peter

https://en.wikipedia.org/wiki/Logarithmic_decrement

well done with the experiment! now get a piece...

Hi Sus - Give it a good coat of wax. I use paste wax and would give it 5 coats of wax for MDF melamine surface.... Peter

Hi Sus - I'd add webs to the long sides. They may bow under hydrostatic pressure. You can test this in FE by adding a hydrostatic load case to the model. MDF is 4000-4500MPa modulus. I presume you...

some more machine fun - Peter

https://youtu.be/q3kw75XCj_4

Double Column Machining Center - HD Video produced by ???? S&J Corp - YouTube

Hi Pio- Not sure if your following the Milli thread. I pursued the exo-portal design and got the weight down to 730kg with all axes 100N/um. It could come down more with some more time. The portal...

Hi Pippin - Same problem once you put an enclosure on so make access same as having an enclosure. The "box" can be taller so the hole is bigger giving good access. Maybe the front of the "box" is not...

Morning all and sundry - Been interested in another thread on a small mill. It has brought back memories of an exoframe design I wanted to look at. So I built a model this morning and its very good....

Hi All - I have been wondering why the Datron NEO is a portal type machine when all their others are gantries. I think its because with a gantry there is always a dead space at the back due to the...

Hi Pio - Another worthwhile configuration is a portal machine like attached. Peter

Hi Pio - You could go the gantry design and cast the base yet use steel for the gantry, that's how Datron do it, except they use granite. Check out your floor loads. A sustained high load on a floor...

Hello BB - The technically correct way to align such a machine is to use a geometric laser metrology set up. Unfortunately they cost well over $25000USD to buy one. Maybe you can hire one nearby you?...

Hi Craig & et al - I ran another couple of rounds. I'm at the point I think where to gain stiffness I have to gain weight. So Round 12 got to 107N/um at 1684kg. I made the base deeper and played with...

Evening All - A little bit more work at Round 10. Couldn't help myself. Wanted to get to 50% weight ie 1360kg but got to 58% at 1578kg. Scored 95N/um would like 100!! But that's enough I can see it...

Evening All - The gist of the matter is I have hovered around 80N/um for this design. I have reduced the weight from 2720kg to 1706kg so that's a loss of 40% would like a little more. But its a...

Hi Craig - As I have stated before any config can be made to any stiffness as long as you have the real estate. So yes making the machine base deeper will make it stiffer in the Y dirn but maybe not...

Hi All - Here's the lightweighting history so far. Still cutting away stuff. I only mod one component at a time so I know what's what. Peter

Evening All - I built a new gantry model which had bearings and features that could be adjusted easily. I then set up 4 freedom cases. I constrained the model at the bearings in 4 cases. So I had a...

Morning Pio - The chase for machining steel using a medium size mill in a 3rd floor apartment, what a set of parameters! So interesting!
Datron is worth a visit. I think that style of machine is...